1. Field of the Invention
The present invention relates to a fluidized-bed equipment formed, in a vessel, with a plurality of regions including a first region high in concentration of a granular or liquid fluidized substance and a second region low in the concentration, to effect various treatments or processings such as combustion, gasification and the like. Further, the invention relates to a pressurized fluidized-bed (combustion) combined cycle apparatus in which coal is burned and gasified within a vessel filled with a fluidized particle, and steam is produced from water by combustion heat, to drive a steam turbine and to drive a gas turbine by exhaust gas.
The invention can be applied to a fluidized-bed gasifier for supplying a coal particle and a gasification agent of coal into a vessel to gasify the coal, a fluidized-bed combustion apparatus for supplying a particle in which industrial wastes are granulated and a gasification agent by which the industrial wastes are burned, into the vessel to burn the wastes, and the like.
Moreover, the invention can also be applied to a fluidized-bed gasifier for a heavy oil, in which the heavy oil and a gasification agent for the heavy oil are supplied into a vessel to gasify the heavy oil, a bioreacter in which a biomass such as plants, chips and the like and a gasification agent for gasifying the biomass are supplied into a vessel and are gasified, and the like. Of course, the invention should not be limited to these arrangements.
2. Description of the Prior Art
It has been known to find a temperature distribution within a vessel in a height direction in order to detect a surface position of a substance put into the vessel. For example, it has been disclosed in Japanese Patent Unexamined Publication No. 59-41705 to arrange a heat transfer portion capable of heat-transferring a temperature difference between a fluidized bed (fluidized particle filled portion) of a fluidized-bed equipment and a free board portion (gas portion), to the outside, to detect a temperature distribution of the heat transfer portion to thereby measure a bed height of the fluidized bed. The prior art can effect the fact that a portion in contact with the fluidized bed and the free board portion are clearly different from each other in metal temperature at the heat transfer portion, to measure the bed height of the fluidized bed.
There are many examples for finding the temperature distribution to detect the surface, which are disclosed in, e.g., Japanese Patent Unexamined Publication No. 1-102395, Japanese Patent Unexamined Publication No. 62-102121, and Japanese Patent Unexamined Publication No. 60-195420.
In addition to the above, it has been known to detect a bed height of a pressurized fluidized-bed equipment by a pressure difference, which is disclosed in a publication.
The prior art in which the temperature distribution within the vessel in the height direction is measured to detect a surface from an abrupt change in the temperature distribution is advantageous for an arrangement in which temperatures are clearly different from each other with the surface serving as a boundary.
However, even if the prior art is applied to an arrangement like the fluidized-bed equipment in which temperatures are not almost different from each other at a boundary between the fluidized bed portion and the free board portion within the vessel, it is impossible to find the bed height.
Furthermore, in the fluidized-bed equipment, a fluidized particle is always fluidized by supply of gas. If the bed height of the fluidized-bed equipment is detected by a pressure difference, a portion deep or thick in fluidized particle is judged as being a fluidized-bed portion, and a portion thin or light in fluidized particle is judged as being a free board portion. It is likewise impossible to find the bed height even if such a prior art is applied thereto.